SEIKO 5 – the meaning of the “5” A great marketer had the idea in the 70ies: to be a SEIKO 5, the watch has to have the following 5 (five) attributes (thus the name SEIKO 5): 1. Automatic, 2. Water resistant, 3. Shock resistant, 4. Date, 5. Day. Please note that some SEIKO 5’s are in truth SEIKO 4’s, if the “Day” function is omitted, then the Caliber 7S25 is used. The only difference to the in most cases found 7S26 is the omission of the day wheel. Also re-issues of SEIKO 5 Sports ceaselessly use the 7S36 caliber. Again the 7S36 is similar to the preferred 7S26, yet it features 23 Jewels as opposed to the 21 Jewels in the 7S26. Please note that a majority of these movements beat at a rate of 21’600 bph (beats per hour) or 6 bps (beats per second). As a comparison, an ETA 2824-2 beats at 28’800 bph or 8 bps. A Miyota 82xx beats at 21’600 bph. Why do I mention these three movements? Because they are found in probably 80% of all inexpensive automatic wrist watches. A market share that is huge, yet challenged in this day and age (2006) by an increasing share of inexpensive China Made automatic movements An automatic watch (also known as a self-winding watch) is a mechanical watch, in most cases with a balance wheel escapement, whose mainspring is wound by the motion of the wearer’s arm, instead of having to be wound manually on a daily basis. Whereas a quartz watch is powered by electricity, a mechanical watch is powered by a mainspring which should be rewound for the watch to keep time.
Japan 23 Jewel Automatic Self Winding Movement (Calibre 7S36)
Stainless Steel Case with Black Nylon Strap
Day/Date Display with Arabic Option, Luminous Hands and Markers, Hardlex Mineral Crystal for Durability
Case Size: 42 mm Diameter, 12 mm Thickness
Water Resistant – 100M, Screw Down Transparent Case Back